Apparatus for and method of reducing concentration of carbon monoxide and fuel-cells generator system with such apparatus

Abstract

The structure of the present invention enables all catalysts packed in a cooling layer to be kept in an active temperature range, thereby sufficiently reducing the concentration of carbon monoxide included in a hydrogen-rich gas. A supply of water is fed through a water inlet pipe 40 to a selective CO oxidizing unit 34 of a reformer 30. The heat of vaporization of the supplied water directly cools down selective CO oxidizing catalysts 50 stored in the selective CO oxidizing unit 34. This enhances the cooling efficiency and enables all the selective CO oxidizing catalysts 50 stored in the selective CO oxidizing unit 34 to be maintained in the active temperature range, thus sufficiently reducing the concentration of carbon monoxide included in a resulting gaseous fuel.

What is claimed is: 
     
       1. An apparatus for reducing concentration of carbon monoxide included in a hydrogen-rich gas, which contains both hydrogen and carbon monoxide, said apparatus comprising: oxidizing gas introducing means for introducing an oxygen-containing oxidizing gas to said hydrogen-rich gas;   an oxidizing unit having a catalyst that enables oxygen included in said oxidizing gas to be bonded to said carbon monoxide included in said hydrogen-rich gas preferentially over hydrogen included in said hydrogen-rich gas; and   water supply means for applying a supply of water onto the catalyst itself.   
     
     
       2. An apparatus in accordance with claim 1, wherein said water supply means comprises a plurality of water supply conduits that enable water to be fed to said oxidizing unit via different pathways. 
     
     
       3. An apparatus in accordance with claim 2, wherein said catalyst in said oxidizing unit is divided into a plurality of groups of catalyst having a predetermined shape, said plurality of groups of catalyst being arranged along a flow direction of said hydrogen-rich gas,   said plurality of water supply conduits being arranged to enable water to be fed to said plurality of groups of catalyst.   
     
     
       4. An apparatus in accordance with claim 1, said apparatus further comprising: temperature detection means for measuring a temperature of said oxidizing unit; and   control means for regulating an amount of water supply by said water supply means, thereby enabling said temperature of said oxidizing unit to be kept within a predetermined range.   
     
     
       5. An apparatus in accordance with claim 1, said apparatus further comprising: carbon monoxide concentration detection means for measuring a concentration of carbon monoxide included in said hydrogen-rich gas;   oxidizing gas supply control means for regulating an amount of oxidizing gas supply by said oxidizing gas introducing means according to said concentration of carbon monoxide; and   water supply control means for regulating an amount of water supply by said water supply means according to said amount of oxidizing gas supply.   
     
     
       6. An apparatus in accordance with claim 5, wherein said water supply control means comprises: water supply calculation means for specifying said amount of water supply by said water supply means in order to hold a predetermined ratio to said amount of oxidizing gas supply.   
     
     
       7. An apparatus in accordance with claim 1, said apparatus further comprising: oxidative reaction detection means for detecting a progress of an oxidative reaction in said oxidizing unit; and   control means for regulating an amount of water supply by said water supply means according to said progress of said oxidative reaction.   
     
     
       8. An apparatus in accordance with claim 7, wherein said oxidative reaction detection means comprises means for measuring a temperature of said oxidizing unit, wherein the oxidative reaction detection means detects said progress of said oxidative reaction based on said temperature of said oxidizing unit. 
     
     
       9. An apparatus in accordance with claim 7, wherein said oxidative reaction detection means comprises means for measuring a flow rate of said hydrogen-rich gas, wherein said oxidative reaction detection means detects said progress of said oxidative reaction based on said flow rate of said hydrogen-rich gas. 
     
     
       10. An apparatus in accordance with claim 7, wherein said oxidative reaction detection means comprises means for measuring a concentration of carbon monoxide included in said hydrogen-rich gas, wherein said oxidative reaction detection means detects said progress of said oxidative reaction based on said concentration of carbon monoxide.